Die-stock.



F. G. KOEHLER.

DIE STOCK.

APPLICAYION FILED FEB. 24. 19H.

Patented Nov. 12, 1918.`

2 SHEETS-SHEE l. EIELJ F. G. KOEHLER.

' DIE STOCK.

APPLICATION FILED FEB.24.19I7. T 1,284,709. Patented mov. 12, 1918.

' 2 SHEETS-SHEEI 2.

Erl-5') 1 /55 AUNIT-ED SIATES PATENT OFFICE.

FREDERICK G. KOE-ILER, OF WARREN, OHIO, ASSIGNOR TO THE BORDEN COMPANY, AOIF WARREN, OHIO, A CORPORATION OF OHIO.

DIE-STOCK.

Specification of Letters Patent.

Patented Nov. 12, 1918.

Application filed February 24, 1917. Serial No. 150,689.

To all 'whom it may concern:

Be it known that I, FREDERICK G. Konn- Lnn, a citizen of the United States, residing at TNarren, in the county of Trumbull and State of Ohio, have invented a certain new and useful Improvement in Die-Stocks, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to die stocks of a type adapted to out tapered threads on pipes. The general object is to provide a. simple effective die stock in which movable chasers are automatically controlled to positively recede the proper amount and which is arranged to accurately govern the relative longitudinal movement of the chasers as they are revolved. n

My invention is hereinafter more fully described, and the essential characteristics are set forth in the claims.

In the drawings, Figure l is a front elevation of my die stock; Fig. 2 is a side elevation of the same; Fig. 3 is an axial section; Fig. 4 is a sectional detail of the menibers cont-rolling the recession of the chasers; Fig. 5 is a sectional elevation of a portion of the die stock showing the parts with the front cover-plate removed; Fig. 6 is a detail of one of the chasers with the ring in engagement therewith.

Describing the parts of my invention by the use of reference characters, l indicates a skeleton frame adapted to hold a pipe embracing bushing 2, shown as secured in position in the frame by a thumb screw 3. The frame 1 is preferably a forwardly extending skeleton portion terminating in an annular flange 5 and a forwardly extending cylindrical portion 6. The portion 6 is threaded on the interior to receive the external threads 'Z of a tubular body or sleeve 8 of the ro- `"tatable portion of my die stock.

As shown the tubular portion 8 carries a housing comprising an outwardlv extending wall 10 carrying forwardly projecting flanges 11 and 12 terminating in the same plane to which is secured a covenplate 14.

The flanges 11 and l2 may be connected at intervals by ribs 16 separated to provide guideways for the chasers 20. The chasers 20 are provided at their inner ends by the usual threads and at an intermediate portion with a shoulder 2l engaging acontrolling ring 22, beneath which the chaser extends outwardly, as at 23. The periphery of the ring 22 may be rotatably embracedy by the flange l2, and the ribs 16 are suitably cut away to provide for the ring lying with its outer face against the cover-plate 14 and its inner face against the extensions of the chasers. i

At the point where the ring 22 engages4 each of the chasers I provide a cam surface 30 sloping outwardly and the shoulders 2l on the chasers are made coinplementary thereto so that relative rotation of the ring may permit outward radial movement of the chasers or cause their inward movement.

To cause the rotation of the ring 22 with relation to the housing I provide on the ring a radial peg 32 adapted to engage a cam slot 3e of a longitudinally extending cani member 35 secured at its rear end to a ring 36 rotatably embracing the cylindrical portion 6 and secured against longitudinal dis-- placement by a circular nut 37. The camv member 35 preferably comprises a halfround bar extending through an opening 40 in the wall l0 which is enlarged radially to provide for the same, the inner or fiat side of the cam member being presented to the periphery of the ring 22.

It is convenient t0 secure the cam bar 35 to the ring 36 by upsetting a reduced end 38 of the bar, which occupies an ear 39 on 'the ring, as shown in Figs. 3 and A. It is also convenient to make the hole 40 round so that it may be readily machined.

It will be seen that as the chasershousing l0 isnioved toward or away from the frame and ring .36, the peg 32, sliding along the inclined slot 34, will travel circumferentially and thus cause the ring 22 to rotate slightly. This will change the radial position of the chaser-abutment-s provided by the cams 30 on the ring. For example, while the chasers 2O are cutting by rotating the housing l0 and body member S (which is accomplishedvby the usual handles 50) the threads 7 will cause the housing to be lOl) moved toward the stationary frame l, which,

ably clamped onto the pipe by the screw 3 extending clear 'through the bushing 2, causes the positive and accurate longitudinal advance of the chasers.

It will be noticed that there is some longitudinal play between the ring 36 and the circumferential groove of the stationary frame which it occupies. During the cutting operation the thrust against the cam bar 35 keeps the ring 36 against the shoulder provided by the flange 5. The clearance on the other side of the ring 36 allows the ring to be iven a' movement toward the chaser housing to let the chasers recede farther. This movement may be of use at the end ott' the cut to insure the chasers clearing the pipe by sufficient amount to enable the pipe to be readily drawn out of the die stock.

After the chasers are removed from a finished thread and the threaded pipe is withdrawn, the housing is again caused to move away from the frame by rotating backwardly, which brings the housing to the outer end of the cam member 35, into the initial position shown in Fig. 3. To prevent dirt, chips, and the like, from entering the housing, I may provide a cover 51 secured by a screw 52 to the cam bar, which cover normally closes the opening, through which the cam bar extends, after each operation. This cover also forms a stop limiting the outward movement of the Chaser-housing and preventing inadvertent separation of the die stock when not in use.

By inclosing the chaser abutment-ring within the annular space in the housing, I protect it from dirt or injury. This ring has its bearing at its outer periphery against the cylindrical inner surface of the wall l2 of the housing. This makes a cheap and easily machined construction. The feature of providing the abutment-shoulder on the chaser by cutting away a portion of such chaser, and allowing the ring to occupy such cutaway portion,'insures accuracy in presentation of the chasers, simplifies the construction and renders the device more comact.

p Having thus described my invention, what I claim is:

1. The combination of a frame adapted to be clamped to the work, a rotatable chaser-carrying frame having a threaded connection with the stationary lrame mentioned, said rotatable frame having an annular groove intersected by radial grooves, chasers occupying the radial grooves and each having a reduced outer portion providing an abrupt shoulder, a ring mounted within the annular groove and bearing at its outer periphery against the outer face of the annular groove and having cams on its inner periphery bearing against the Chaser shoulders, there being a longitudinal recess through the chaser-carrying frame communieating with the annular stationary frame, and a bar carried by said ring and extending through the longitudinal recess, said bar having an inclined engagement with the cam ring, whereby the ring is rotated as the Chaser-carrying frame travels longitudinally of the bar.

2. In a die stock, the combination of a frame adapted to be clamped to a pipe to be threaded, a rotatable housing, a threaded sleeve on one of such members coacting with threads on the other, chasers carried by the housing, an abutment ring carried by the housing having a cani engagement with the chasers, a ring rotatably mounted on the frame, a bar carried by the last mentioned ring extending through an opening in the housing and having a cam slot occupied by a lug on the chaser-abutment ring, and a plate secured to the forward end of said bar and overhanging the opening which the bar occupies and thus forming a stop against outward movement ol the housing.

3. In a die stock, the combination of a frame adapted to be clamped to a pipe to be threaded, a rotatable housing, a threaded connection between the frame and housing, a ring carried by the frame, a substantially half-round bar secured to said ring and extending parallel with the axis of the die stock and occupying a round opening in the housing and having a flat surface toward the axis of the die stock and a diagonal slot in its flat surface, chasers carried by the housing, and a ring within the housing having a cam engagement with said chasers and having a lug occupying said diagonal slot in the bar.

In testimony whereof, I hereunto affix my signature. d FREDERICK G. KOEHLER. -f

Copiesof this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

